This invention relates to alternator tuning devices, particularly to alternator isolating decoupler (AID) pulleys with torsion springs for isolation. The function and utility of alternator tuning devices is commonly known. Today's commercially available AID devices have an isolating spring, one way clutch, bearing(s), a pulley and certain other components. The need for each of these components typically requires the overall size diameter of the device to exceed what the industry desires. With todays ever smaller automotive engine sizes and ever increasing fuel efficiency requirements, there is a need for AID devices that have a reduced pulley diameter while meeting the required functionailty.
Representative of the art is U.S. Pat. No. 7,153,227 which discloses a decoupler for an alternator pulley in a serpentine drive system has a resilient, helical spring member that couples the alternator pulley with a hub structure through a spring retaining member. A bushing is disposed between the spring retaining member and the hub structure to facilitate sliding engagement therebetween. An annular sleeve member is disposed between the spring member and the alternator pulley to facilitate sliding engagement therebetween. The spring member is connected at one end thereof to the hub structure and connected at an opposite end thereof to the spring retaining member. The resilient spring member transmits the driven rotational movements of the alternator pulley by the serpentine belt to the hub structure such that the alternator shaft is rotated in the same direction as the alternator pulley while being capable of instantaneous relative resilient movements in opposite directions with respect to the alternator pulley during the driven rotational movement.
Also representative of the art is applicant's copending U.S. non-provisional application Ser. No. 13/541,216 filed Jul. 3, 2012.
What is needed is an isolator decoupler having a pulley journalled to a shaft on a low friction bushing and journalled to a spring carrier on a low friction bushing, which spring carrier is journalled to the shaft on a low friction bushing. The present invention meets this need.